Method of recycling Cd-112 isotope

ABSTRACT

Cd-112 isotope is recycled from a Cd-112 chemical separated solution or a remainder of an electroplating solution having a Cd-112 target. The present invention recycles Cd-112 isotope with a low cost, a high purity and a high recycle rate. The recycled Cd-112 isotope can be easily stored. And, the Cd-112 isotope can be used as an imaging agent in nuclear medicine.

FIELD OF THE INVENTION

The present invention relates to recycling Cd-112 isotope; moreparticularly, relates to obtaining a cadmium hydroxide (Cd(OH)₂)precipitation by reacting a hydroxide with a chemical separated solutionof a Cd-112 target or a remainder of an electroplating solution having aCd-112 target and thus recycling Cd-112 isotope through filtrating andrinsing the reacted solution having the Cd(OH)₂ precipitation.

DESCRIPTION OF THE RELATED ART

In-111 isotope has a nuclear characteristic of trapping electron andreleasing two γ-radiation characteristic energy spectrum. Because it hasa short half life and a proper energy, the In-111 isotope is widely usedin a nuclear single photon emission computerized tomography (SPECT) todiagnose human body diseases and aid in bio-researches.

Some labeled compounds of In-111, like ¹¹¹InCl3, ¹¹¹In-bleomysin and¹¹¹In-DTPA octreotide, are used to diagnose a local tumor of an organ.Lipophilic complex compound of ¹¹¹In-oxine can label leukocytes forimaging a gathering and diagnosing nidus of an inflammation. Complexcompounds made of ¹¹¹In together with monoclonal antibody, platelet,globulin or recombinant tissue plasminogen activator (γt-PA) and Fab,(Fab′)₂ (immunoglobulin fragments) are potential imaging agents newlydeveloped with excellent applications for scanning myocardial infarctionand thrombus and for doing bio-researches concerning thrombin and renalfunctions.

In-111 is generally obtained from ¹¹²Cd(p,2n), ¹¹¹Cd(p,n),^(nat)Cd(p,xn), ¹¹⁰Cd(d,n) or ¹⁰⁹Ag(a,2n), where the first one has thebest production by using a solid ¹¹²Cd target having a high isotopeenrichment with a proper target thickness (˜100 μm) and a proper protonbeam energy (˜22 MeV).

For fabricating ¹¹¹In-DTPA octreotide for nuclear medicine through acyclotron, Cd-112 isotope is required. However, the Cd-112 isotope isnot easy to be obtained and its cost is high. Hence, the prior art doesnot fulfill all users' requests on actual use.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to recycle Cd-112 isotopewith a low cost, a high recycle rate and a high purity.

To achieve the above purpose, the present invention is a method ofrecycling Cd-112 isotope, where Cd-112 isotope is recycled through stepsof: (a1) adding a sulfide solution into a remainder of an electroplatingsolution having a Cd-112 target to obtain a precipitation of cadmiumsulfide (CdS); (b1) adding hydrochloric acid into the CdS precipitationto obtain a solution of cadmium chloride (CdCl₂); (c1) adding a solutionof hydroxide into the CdCl₂ solution to obtain a Cd(OH)₂ precipitation;and (d1) filtrating and rinsing the Cd(OH)₂ precipitation; or, throughsteps of: (a2) mixing a chemical separated solution of a Cd-112 targetand a cadmium bromide (CdBr₂) solution to obtain a mixed solution; (b2)adding a solution of a hydroxide into the mixed solution to obtain aCd(OH)₂ precipitation; and (c2) filtrating and rinsing the Cd(OH)₂precipitation. Accordingly, a novel method of recycling Cd-112 isotopeis obtained.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The present invention will be better understood from the followingdetailed descriptions of the preferred embodiments according to thepresent invention, taken in conjunction with the accompanying drawings,in which

FIG. 1 and FIG. 2 are the views showing the first preferred embodimentand the second preferred embodiment according to the present invention.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

The following descriptions of the preferred embodiments are provided tounderstand the features and the structures of the present invention.

Please refer to FIG. 1, which is a view showing a first preferredembodiment according to the present invention. As shown in the figures,the present invention is a method of recycling Cd-112 isotope,comprising the following steps:

(a1) Obtaining a CdS precipitation 11: A sulfide solution is added to aremainder of an electroplating solution having a Cd-112 target to obtaina precipitation of cadmium sulfide (CdS), where the sulfide solution isa solution of sodium sulfide (Na₂S).

(b1) Forming a CdCl₂ solution 12: Hydrochloric acid is added to theprecipitation of CdS to form a solution of cadmium chloride (CdCl₂).

(c1) Obtaining a Cd(OH)₂ precipitation 13: A hydroxide solution is addedto the CdCl₂ solution to obtain a precipitation of cadmium hydroxide(Cd(OH)₂), where the hydroxide solution is a solution of sodiumhydroxide (Na(OH)) or a solution of potassium hydroxide (K(OH)).

(d1) Recycling Cd-112 isotope 14: The Cd(OH)₂ precipitation is movedinto a semi-automatic vacuum filtration system to be filtrated andrinsed for recycling Cd-112 isotope.

Please refer to FIG. 2, which is a view showing a second preferredembodiment. As shown in the figures, the present invention is a methodof recycling Cd-112 isotope, comprising the following steps:

(a2) Obtaining a mixed solution 21: A chemical separated solution of aCd-112 target and a cadmium bromide (CdBr₂) solution are mixed to obtaina mixed solution.

(b2) Obtaining a Cd(OH)₂ precipitation 13: A hydroxide solution is addedto the mixed solution to obtain a precipitation of Cd(OH)₂, where thehydroxide solution is a solution of Na(OH) or a solution of K(OH).

(c2) Recycling Cd-112 isotope 14: The Cd(OH)₂ precipitation is movedinto a semi-automatic vacuum filtration system to be filtrated andrinsed for recycling Cd-112 isotope.

The Cd-112 isotope recycled by the above two embodiments can be calcinedto obtain a solid cadmium oxide (CdO); or can be added with a solutionof cyanide and an alkaline solution to obtain an electroplating solutionhaving a Cd-112 target, where the Cd-112 isotope can be easily stored.The recycle rate of Cd-112 isotope through using the present inventionis more than 98% with a purity rate more than 99%.

To sum up, the present invention is a method of recycling Cd-112isotope, where Cd-112 isotope is recycled with a recycle rate more than98% and a purity rate more than 99%; and, thus, a cost for purchasingCd-112 is reduced and further a cost for a nuclear medicine is loweredas well.

The preferred embodiments herein disclosed are not intended tounnecessarily limit the scope of the invention. Therefore, simplemodifications or variations belonging to the equivalent of the scope ofthe claims and the instructions disclosed herein for a patent are allwithin the scope of the present invention.

1. A method of recycling Cd-112 isotope, comprising steps of: (a1)adding a sulfide solution into a remainder of an electroplating solutionhaving a Cd-112 target to obtain a precipitation of cadmium sulfide(CdS); (b1) adding hydrochloric acid into said precipitation of CdS toobtain a solution of cadmium chloride (CdCl₂); (c1) adding a solution ofhydroxide into said solution of CdCl₂ to obtain a precipitation ofcadmium hydroxide (Cd(OH)₂); and (d1) filtrating and rinsing saidprecipitation of Cd(OH)₂ to recycle Cd-112.
 2. The method according toclaim 1, wherein said sulfide solution is a solution of sodium sulfide(Na₂S).
 3. The method according to claim 1, wherein said solution ofhydroxide is selected from a group consisting of a solution of sodiumhydroxide (Na(OH)) and a solution of potassium hydroxide (K(OH)).
 4. Themethod according to claim 1, wherein said recycled Cd-112 is calcined toobtain solid cadmium oxide (CdO).
 5. The method according to claim 1,wherein said recycled Cd-112 is added with a solution of cyanide and analkaline solution to obtain an electroplating solution having a Cd-112target.
 6. A method of recycling Cd-112 isotope, comprising steps of:(a1) mixing a chemical separated solution of a Cd-112 target and acadmium bromide (CdBr₂) solution to obtain a mixed solution; (b2) addinga solution of a hydroxide into said mixed solution to obtain aprecipitation of Cd(OH)₂; and (c2) filtrating and rinsing saidprecipitation of Cd(OH)₂ to recycle Cd-112.
 7. The method according toclaim 6, wherein said solution of hydroxide is selected from a groupconsisting of a solution of Na(OH) and a solution of K(OH).
 8. Themethod according to claim 6, wherein said recycled Cd-112 is calcined toobtain solid CdO.
 9. The method according to claim 6, wherein saidrecycled Cd-112 is added with a solution of cyanide and an alkalinesolution to obtain an electroplating solution having a Cd-112 target